The ability to uniformly apply an element onto a micron or sub-micron particulate allows for the development of a new class of materials that may be used to engineer coatings and/or bulk materials with greater precision. The industry and military have requirements for the production of encapsulated particulates, having diameters in the range of 1-10 μm, which have a high-purity, uniform coating over the entire surface area of the particulate. These size particulates, which fall into Geldart's Class C category of particulate material, often have high aspect ratios and cause particular problems when attempts are made to consolidate them, since they tend to agglomerate and are difficult to handle and process. An ability to control the thickness of the coating is a requirement, as well as an ability to economically produce at high-volume production rates (thousands of pounds). These materials could then be used by the military to produce weapons with greater lethality and to solve a variety of problems that have plagued the armed forces and the commercial sector for years, such as lead-based munitions. The development of this technology will also provide for significant advances in combustion and propulsion science, resulting in the production of munitions with greater scaled lethality.
There are two major challenges in manufacturing encapsulated powders for cold spraying applications with controlled surface properties; or, if multiphase powders are produced, with controlled phase distribution to be used for manufacturing environmentally friendly ammunitions including bullets. The first challenge is that these powders are in the size regime of 1-10 μm (Geldart's Class C category of particulate material), which makes them very cohesive and difficult to handle, fluidize, and process in a non-agglomerated form. Thus, obtaining a uniform coating from this process becomes extremely difficult due to undesirable hard agglomerates. The second challenge is to produce these coatings at a reasonable cost. Currently, the cost of manufacturing these powders is prohibitive, limiting their useful applications.